Drawing-press.



J. E. DOBSON.

DRAWING PRESS.

APPLICATION FILED JUNE 26. 1915. I 1 2ml, Patented Jan.16,1917.

3 SHEETS-SHEET I.

INVENTOR J. E. DOBSON.

DRAWING PRESS.

APPLICATION FILED JUNE 26. 1915. 1,212,192, Patented Jan.16,1917.

s SHEETS-SHEET 2.

Z INVENTOR WITNESSES; fl Z flw o m- By Attorneys,

J. E. D'OBSON.

DRAWING PRESS.

APPLICATION FILED JUNE 26. 1915.

1,2} Patented Jan. 16,1917.

3 SHEETS-SHEET 3 INVENTOR I Aizorne 5, W

JOHN E. DOBSON, OF NEW YORK, N. Y., ASSIGNOR TO E. W. BLISS COMPANY, OFBROOKLYN, NEW YORK, A CORPORATION OF WEST VIRGINIA.

DRAWING-PRESS.

Specification of Letters Patent.

Application filed June 26, 1915. Serial No. 36,456.

- To all whom it may concern Be it known that I, Jorm E. DOBSON, acitizen of the United States of America, residing in the borough ofManhattan, city, county, and State of New York, have in vented certainnew and useful Improvements in Drawing-Presses, of which the followingis a specification.

My invention has relation to a drawing press and provides desirableimprovements therein whereby variation in the parts during the dwell ispractically completely overcome. Likewise, whereby the press may be runat a higher speed without injuring the blank and whereby torsionalstrain upon the press is obviated, the number of parts'is reduced and acrank shaft is dispensed with.

These and other objects which will be set forth as the descriptionprgceeds are accomplished by the aid of my invention, which consists inproviding direct driving connections from crank pins on each side of thepress to the punch and in providing operating connections on each sideof the press to a movable table from the same crank pins throughinterposed toggles whereby variation during the dwell of the table isobviated, and a simple, durable and efiicient press is provided whereinthe working parts are reduced to a minimum and torsional strain andstress is obviated, and an improved construction produced.

The most desirable form of my invention known to me is illustrated inthe accompanying drawings.

In said drawings, Figure 1 is a side elevation of a press constructedaccording to my invention partly in section and partly broken. Fig. 2 isa front elevation thereof. Fig. 3 is a cross section on the line 33 Fig.

V 1. Fig. 4 is a diagram illustrating the toggle movements, and Fig. 5is a diagram of the -movements of the operating crank pin.

My invention is illustrated as applied to a press having side frames A,A mounted upon a suitable base B and connected at their upper ends by aframe C. Between these side frames A, A is located the stationary blankholder D, which is adjustably supported from the frame C by threadedbolts d having nuts d, d on respective sides of the blank holder. Amovable punchcarrying-slide Eis reciprooated in slides e and is attachedto an overhead cross head F by adjustable connections including athreaded rod f having adjusting nuts 7, P. A movable table G isreciprocated vertically and slides on ways provided by the side framesA, A

The foregoing is a known type of press in connection with which I haveillustrated my invention.

According to my invention crank pins H, H located on rotary members X, Xare provided upon the respective sides of the machine and directoperating connections from these crank pins to the punch are obtained bylinks I, I which are connected to the cross head F. From the same crankpins the table is driven and the operating means for the table comprisefirst toggles which are operatively connected to the crank pins on eachside, and third toggles which are connected to the table and operatingconnections between the toggles including second toggles comprising aslide. In the manner of constructing my invention which is illustratedin the accompanying drawings the first toggles which are located on eachside of the machine and are lettered J, J (Figs. 1 and 3) are connectedat one end to a rock shaft K which is rocked through links L, L

connected to each crank pin and to rocking arms M, M on the rock shaftK. The table G is provided with vertically placed third toggles whichare preferably located at each corner thereof and are four in number andare lettered N, N N Table to gle which would be lettered N is hidden romview. The table or third toggles are connected to rock shafts O, Osituated at the front and rear of the machine respectively. These rockshafts O, O have rocking operating arms P, P which are four in number,and of which two are seen in Fig. 1. Operating arms P, P and operatingarms M, M are fixed to their respective rock shafts. Links Q connect thearms P to the first toggles J and a slide R which is mounted to slide inthe base B of the machine is pivotally con- Patented Jan. 16, 1917.

. nected to the toggle J. The links Q, o and slide R in effectconstitute second toggles and the slide likewise provides means wherebythe table operating toggles at the front of'the machine are operated,and for this purpose the links Q are pivotally mounted to the front ofthe said slide and to the arms P. The slide support provides an abutmentfor the links Q, Q The rock shaft K is pivotally mounted in an extensionB of the base B which is strengthened by stay rods S, S against alongitudinal strain during operation. Vertical stay rods T, T connectthe base B and the frame C and extend through each frame A A It will beperceived from the foregoing drawings that the vertical movement of thepunch as it hits the work, takes place during the time the crank pin isdescending from its extreme uppermost position substantially 45, butowing to the are this is only one-eighth of the total vertical move-'ment of the crank pin and accordingly the punchis moving very slowlywhen it hits the blank, and thereby I am enabled to run the press at agreatly increased speed. I have illustrated in Fig. 5 a diagram of thepositions occupied by the crank pin during the performance of thevarious functions of its connected operating devices. The start is madeat substantially zero which it Will be perceived is about 45 'short ofthe top or high point of the crank pin, and as stated the crank pin,when the punch hits the blank, is moving from its uppermost position tothe point marked 85, and during this time the table is moved up to thework. At point 85 as seen in Fig. 1, toggles N, N N N are straight andthe punch is then in the contact with the blank. The dwell of the tablebegins at 85 and continues to the point marked 235 occupyingsubstantially 145. During this time the punch is drawn down by the crankpins to perform its function. The travel of the crank pin during thedwell is, therefore, from 85 to 235. These points are both on the sameside of a diametrical line 11 (Fig. 5) which is drawn on the circle ofrotation of the crank pin and is perpendicular to the mean longitudinalaxis 22 of the connecting link. The are traversed by the crank pinduring the dwell of the table is less than half the circumference of itscircle of rotation, and the longitudinal movement of the link is lessthan a radius of the crank pins circle of rotation. By this means aminimum of movement is communicated from the crank pin to the arms M, Mduring the period of dwell.

According to my invention I provide means whereby the amount ofvariation or movement of the table during dwell is reduced so that thesame is practically nonexistent. In a press of a given size wherein forinstance the diameter of the path of rotation of the crank pin is 24inches, the toggle vibration at U is approximately 10 lnches or 5 incheseach side of the center. This results in a longitudinal movement at thepoint V of 1%; inches giving a vibration of the second toggle of a of aninch each side of the center. This is further reduced to a movement ofthe third series of toggles at the point W of eight onethousandths of aninch (.008) or four one thousandths (.004) at each side of the centerand the vertical movement or variation therefore of the table during theperiod of dwell is reduced to three one millionths (000,003) of an inch.It will be perceived therefore that this variation or movement of thetable during dwell is so slight as to be incapable of detection by itseffect upon the work or in any other way except by calculation and thatthe table is therefore practically immovable during the dwell.

The rotary main gears X, X upon which the crank pins are mounted asillustrated, are on a shaft X (Fig. 3) and are driven by pinions Y onshaft Y Gear Y on shaft Y is driven from pinion Z on shaft Z carryinggear Z which meshes in pinion Z on the driving shaft Z Upon this drivingshaft are pulleys Z a clutch Z and a balance wheel Z. The shaft Z 'ismounted in posts Z", Z.

Although I have described with great particularity the construction ofmyinvention it is obvious that the same is subject to change within theskill of the mechanic and that equivalent devices may be substituted forthose illustrated, and the said devices may be differently arrangedwithin the limits of the appended claims or applied to other types ofpresses. My invention is not concerned with the details of constructionof the frame of the press or of the means of conveying motion to thecrank pins although the same has been carefully described.

What I claim and desire to secure by Letters Patent is 1. In a drawingpress, a movable table, and a pair of rotary members located on oppositesides of the press, a crank pin on each rotary member, a rock shaft,connections from each crank pin to said rock shaft, and duplicate trainsof toggles between said rock shaft and said table.

2. In a drawing press, a movable table and a crank pin on each side ofthe press, and operating connections between said respective crank pinsand said table comprising a rock shaft, a rocking connection theretofrom each crank pin, and a plurality of trains of toggles between saidrock shaft and said table.

3. In a drawing press, a crank pin on each side of the press, a movabletable and connections thereto from said respective crank pins comprisinga rock shaft having a rocking connection to both of said crank pins, a

toggle connected to said rock shaft, a toggle connected to the table andto a second rock shaft, and a rocking connection between the firsttoggle and the second rock shaft comprising a sliding abutment pivotallyconnected to the first toggle, and a toggle link pivotally connected tosaid slide, and a rock- 1 ing arm on said second rock shaft andpivotally connected to said toggle link.

fl. In a drawing press, a movable table and a crank pin on each side ofsaid press for driving said table, and operating connections betweeneach of said crank pins'and said movable table comprising a rock shaft,

'a rocking connection from each crank pin thereto, a sliding abutment,two toggles connecting said sliding abutment and rock shaft, aseco-ndrock shaft, two toggles connecting the same and the table, rocking armson said second rock shaft and two toggle links connecting the slidingabutment and said rocking arms; I

5. In a drawing press having side frames,

..a movable table, maingears on the outside of each side of thefr'ame, acrank pin on.

each gear and operating connections bea tween each of said crank pinsand said table comprising a rock shaft, a link connected-to each of saidcrank pins for rocking said shaft, a slide and toggles operativelconnected to said rock shaft and said sli e, sec-' ond rock shafts atthe front and rear of the 1 press, ,toggles between said second rockshafts and each corner of the table and rocking connections between saidslide and said table toggles.

a 6. In a drawing press, a movable table 40 and acrank pin on each sideof said press for driving said table, and operating connections betweeneach of said crank pins and said-movable table comprising a rock shaft,a rocking connection from each crank pin thereto, a sliding abutment,two toggles connecting said sliding abutment and rock shaft, a pair ofsecond rock shafts at the front and rear of the machine respectively,two toggles connected to each of said rock shafts and the table, tworocking arms on each of said second rock shafts,'and four toggle linksconnecting said sliding abutment and said rocking arms.

7. In a drawing press, a movable punch and a movable table, a crankpinfor driv- V ing both of said parts, a linkdirectly connecting thecrank pin and punch and a driving connection between the crank pin aridtable including a plurality of connefited toggles, a link connecting thecrank pi to 1 the first toggle, a third toggle connected to the table,and a connection between said first and third toggles comprising a slideto which the first toggle is pivota a second toggle-arm pivoted to saidslide,

ly connected'ga; v

-the parts so ar ranged and disposed that the 130 and a rocking armpivotally connected to said second toggle arm" and operatively connectedto the third toggle.

8. In a drawing press, astationary blank holder, a movable punch, amovable table, a crank pin on each side-0f the press and di rect drivingconnections from each of said crank pins to said punch and drivingconnections from each of said crank pins to said table.

q 9. In a drawing press, a movable punch,

a crank pin on each side of the machine, a movable cross head carryingthe punch and a link directly connecting each crank pin with said crosshead, a movable table and so driving connections thereto from said crankpins, comprising a rock shaft having a rocking connection to each ofsaid crank pins,

a toggle connected to said rock shaft, a: toggle connected to the tableand to a seoond rock shaft, and a rocking connection bletvfveen thefirst toggle and the second rock 10. In a drawingpress, a movabledrawing member, a crosshead therefor, a crank 96 for operating saiddrawing member, and a link directly connecting said .crank andcrosshead, said parts so connected that the drawing member contacts withthe blank at not more than approximately 50 of the r movement of saidcrank past its highest point whereby such contact takes place during theslower rate of travel toward the work of the drawing member.

1-1. 'In a drawing press, a-movablepunch, 100

v a crank pin for operating said punch and a driving connection betweensaid parts,

said parts so connected that the punch contacts with the blank duringthe early part of the movement of said crank pin pastits highest pointwhere y such contact takes place during the slower period of traveltoward the work of the punch, a movable table, a driving connectionbetween the crank pin and table including a succession of operativelyconnected to gles connected to said table and to said cran pin, theparts so arranged and disposed'that the dwell of the table occurs whilethe crank pin is trav-- eling in'its arc of rotation on one side of aline intersecting the center of rotation of the crank pin andperpeiidicular to the mean longitudinal axis ofisuch connection, wherebythe longitudinal movement of suchconnection is not greater than theradius of the circle of rotation of, the crank pm and the table issubstantially deprived of all varlation relative to the work during thedwell.

12. In. a drawing press, a movable table, a table operating crank pin, adr vlng connectionbetween the parts, including a succession ofoperativey connected toggles, a connection .at one end of said togglesto the table and at the 0 her end to the crank pm,

dwell of the table occurs while the crank pin signed my name in thepresence of two subscribing witnesses.

JOHN E. DOBSON. -Witnesses:

CURTIs T. ZIEGLER, EDW. C. REDHEAD.

